2 cups package semisweet chocolate chips
1/2 cup butter or margarine
1 cup sugar
1 1/4 cups all-purpose flour
1 teaspoon vanilla
1/2 teaspoon baking powder
1/2 teaspoon salt
3 eggs (beaten)
1 cup chopped nuts, if desired
Heat oven to 350º. Heat chocolate chips and butter in 3-quart saucepan over low heat, stirring frequently, until smooth; remove from heat. Stir in remaining ingredients except nuts. Stir in nuts. Spread batter in ungreased rectangular pan, 13×9 inches. Bake 25-30 minutes or until center is set. Cool completely.